Mice Immunized with the Vaccine Candidate HexaPro Spike Produce Neutralizing Antibodies against SARS-CoV-2

Updated and revised versions of COVID-19 vaccines are vital due to genetic variations the SARS-CoV-2 spike antigen. Furthermore, that safe, cost-effective, logistic-friendly critically needed for global equity, especially middle- low-income countries. Recombinant protein-based subunit against have been reported using receptor-binding domain (RBD) prefusion trimers (S-2P). Recently, a new version trimers, named HexaPro, has shown possess two RBD in “up” conformation, its physical property, as opposed just one exposed found S-2P. Importantly, this HexaPro antigen is more stable than S-2P, raising feasibility logistics supply chain. Here, we report protein offers promising candidate vaccine. Mice immunized by recombinant adjuvanted with aluminum hydroxide prime-boost regimen produced high-titer neutralizing antibodies up 56 days after initial immunization live infection. Also, level neutralization activity comparable convalescence sera. Our results indicate vaccine confers sera collected from mice receiving regimen.